package com.hcb.micro.sdk.weixin.util;

import java.net.URLDecoder;
import java.security.MessageDigest;
import java.util.Iterator;
import java.util.Map;
import java.util.Random;
import java.util.Set;
import java.util.SortedMap;

/*
 '============================================================================
 'api说明：
 'createSHA1Sign创建签名SHA1
 'getSha1()Sha1签名
 '============================================================================
 '*/
public class Sha1Util
{
    
    public static String getNonceStr()
    {
        Random random = new Random();
        return MD5Util.MD5Encode(String.valueOf(random.nextInt(10000)), "UTF-8");
    }
    
    public static String getTimeStamp()
    {
        return String.valueOf(System.currentTimeMillis() / 1000);
    }
    
    // 创建签名SHA1
    public static String createSHA1Sign(SortedMap<String, String> signParams)
        throws Exception
    {
        StringBuffer sb = new StringBuffer();
        Set es = signParams.entrySet();
        Iterator it = es.iterator();
        while (it.hasNext())
        {
            Map.Entry entry = (Map.Entry)it.next();
            String k = (String)entry.getKey();
            String v = (String)entry.getValue();
            sb.append(k + "=" + v + "&");
            // 要采用URLENCODER的原始值！
        }
        String params = sb.substring(0, sb.lastIndexOf("&"));
        // System.out.println("sha1 sb:" + params);
        return getSha1(params);
    }
    
    // Sha1签名
    public static String getSha1(String str)
    {
        if (str == null || str.length() == 0)
        {
            return null;
        }
        char hexDigits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
        
        try
        {
            MessageDigest mdTemp = MessageDigest.getInstance("SHA1");
            mdTemp.update(str.getBytes("GBK"));
            
            byte[] md = mdTemp.digest();
            int j = md.length;
            char buf[] = new char[j * 2];
            int k = 0;
            for (int i = 0; i < j; i++)
            {
                byte byte0 = md[i];
                buf[k++] = hexDigits[byte0 >>> 4 & 0xf];
                buf[k++] = hexDigits[byte0 & 0xf];
            }
            return new String(buf);
        }
        catch (Exception e)
        {
            return null;
        }
    }
}
